1. Field of the Invention
The present invention relates to a capacitance pressure sensor.
2. Related Background Art
A capacitance type pressure sensor is known in the art. In a temperature regulated capacitance type pressure sensor, a heater is used to maintain the temperature of temperature-sensitive elements. Japanese Patent Application Laid-Open No. 2007-86002 discloses a capacitance type pressure sensor in FIG. 7, in which the substrate has a heater provided therein.
Japanese Patent Application Laid-Open (Translation of PCT Application) No. 2008-527313 discloses a pressure sensor wherein a steel film provided with distortion gauge resistor elements is mounted on a Low Temperature Co-fired Ceramics (LTCC) substrate. While the pressure sensor of Japanese Patent Application Laid-Open (Translation of PCT Application) No. 2008-527313 is not a type of a capacitance pressure sensor, it is taught that the thermal expansion coefficient of the LTCC-substrate is coincident with that of the steel film which is distorted by a pressure.
However, Japanese Patent Application Laid-Open No. 2007-86002 does not specifically describe traces which are connected to the fixed electrode and the heater, in the pressure sensor. Similarly, Japanese Patent Application Laid-Open (Translation of PCT Application) No. 2008-527313 also does not specifically describe the traces in the pressure sensor using the LTCC substrate.